Ambient noise may sometimes interfere with the delivery of audio information. In a two-way communication system for example, in which the far-end talker is at a location remote from the near-end listener, the far-end talker, ignorant of the noise conditions at the listener's location, may not take measures to compensate for the occurrence of disruptive noise events (instantaneous or sustained) at the listener's location. For example, the talker, unaware of a passing car at the listener's location, may not raise his/her voice to maintain audibility to the listener, and the talker's words may not be heard or understood by the listener, even if the system were electrically and mechanically capable of handling such compensation. The inability of the listener to discern the talker's speech under such circumstances is due to the well known psychophysical phenomenon called “masking”—that is, when loud enough, the local noise covers up, or masks, the played-back far-end sound signal. This problem is not limited to two-way communication systems of course, and ambient noise may similarly interfere with pre-recorded voices or any pre-stored audio information that is being played back.